Author Topic: Science  (Read 19169 times)

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Offline Jim Davis

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Re: Science
« Reply #60 on: January 23, 2016, 06:50:41 pm »
Yes the frozen moisture in green wood keeps the splitting maul from losing energy by crushing the wood. Far and away the best situation for splitting wood.

Jim Davis
Jim Davis

Kentucky--formerly Maine

Offline willie

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Re: Science
« Reply #61 on: January 23, 2016, 08:11:01 pm »
looks like a nice place you had there, Jim. Bet you don't miss having to get up that much firewood now a days
« Last Edit: January 24, 2016, 03:27:16 am by willie »

Offline PlanB

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Re: Science
« Reply #62 on: January 24, 2016, 09:37:13 am »
Still interested if anybody up on the science of wood structure knows whether cut green hardwood, if frozen, suffers structural damage at the microscopic level compared to dried wood subjected to freezing.

Also since willie's link mentions cellular changes in lipids and proteins to prepare for winter, whether winter cut green wood would be less subject to cellular level freeze damage (if it exists) than summer cut green wood.

Splitting frozen firewood in winter I'm very familiar with. And I own an old green tractor, too! Cool photo. :)

I love it when a plan B comes together....

Offline Jim Davis

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Re: Science
« Reply #63 on: January 24, 2016, 09:41:10 am »
Plan B, I can't imagine why freezing would damage cut wood, when it doesn't damage standing timber. I had staves in my shed all the time in Maine and never had subzero temperatures hurt it.
Right you are Willie. I didn't mind feeding the stove, but I sure don't miss having to drive in half a dozen storms a ,or having to get the driveway cleared to go to work, or coming home from work at 1 a.m. to a driveway I could barely get into!

That's an early picture of the house. It got a deck and all decked out and pretty later, but that's WAY off topic. I'm very glad I Don't have to worry about it any more.

Jim
Jim Davis

Kentucky--formerly Maine

Offline PlanB

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Re: Science
« Reply #64 on: January 24, 2016, 10:22:03 am »
Asharrow, thanks, I'm not saying it makes a difference .....I'm asking if it does.

The link willie gave indicates that a living northern hardwood tree takes active measures to change some of its internal chemistry. reduce free water content, etc. in order to prepare for winter. So I'm asking if that type of timber,cut in a warmer month, which hasn't taken these internal biological measures might see some internal structural damage and reduced physical properties. Maybe so, maybe not, I personally don't know .... that's why I'm asking.

Here's why I'm thinking about it. Some woods which grow well further south of here -- I think hickory is an example -- you guys know which ones better -- don't work well as bows subjected to subfreezing use. Some others, like Finnish birch bows , made from woods which grow far more northerly, apparently do well in subarctic areas.

So what's the difference in the woods internally, and were they cut for bow use in summer or winter. Lots of interesting questions to me since, those very woods grow here, and maybe I'd like to shoot 12 months of year without worrying so much about the selfbows I make for that.
I love it when a plan B comes together....

Offline willie

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Re: Science
« Reply #65 on: January 24, 2016, 05:20:12 pm »
Plan B

I do not have an opinion based on science, but just a few observations. Having worked with quite a bit of wood in some really cold conditions, I would say that frozen wet wood seems to often have internal  stresses not found when warmer. The example above of the firewood birch round is typical. I think Jim is right to a point about most all wood being easier to split when cold, but I have observed green birch with good bark do strange things when cold. Splits travel almost by themselves once started. I once was removing the bark from spring cut (warmer) birch, and as I released the hoop tension in the outer bark, I could actually watch splitting in the inner layers, follow my knife. My guess is that there are often pressures in trunk associated with different conditions. The article mentions 900 psi. And as far as being detrimental, I guess it's a matter of degree. I have heard of cottonwood trees (cottonwood is very wet when green) "exploding" during rapid temperature drops in the mid west. "Exploding" probably being a bit of overstatement, so under more normal conditions, perhaps trees can adjust to freeze/thaw conditions faster than you might expect.

I have shot self bows in very cold conditions, and have always been leery of "cold breakage", but have never had one break (hickory board bow included) in a way that suggested cold might be a factor. but you can find a lot of opinions on this. Also, my worst cold weather enemy seems to be low winter humidity